Migrants sit in a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) as they arrive alongside the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. Some 118 migrants were rescued from a rubber dinghy off Libya on Monday morning. The Phoenix, manned by personnel from international non-governmental organisations Medecins san Frontiere (MSF) and MOAS, is the first privately funded vessel to operate in the Mediterranean. (Photo by Darrin Zammit Lupi/Reuters)

Migrants are helped to cross from their rubber dinghy to a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants are helped to cross from their rubber dinghy to a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants are helped to board the Migrant Offshore Aid Station (MOAS) ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Medecins san Frontiere (MSF) medics examine a semi-conscious migrant who was brought onto the Migrant Offshore Aid Station (MOAS) ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants on a rubber dinghy wait to be rescued by the Migrant Offshore Aid Station (MOAS) ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants are brought to the Migrant Offshore Aid Station (MOAS) ship MV Phoenix on a MOAS RHIB (Rigid-hulled inflatable boat) after being rescued, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants reach out to grab hold of Migrant Offshore Aid Station (MOAS) rescuers on a RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Tunisian fishermen retrieve a rubber dinghy to take its outboard engine after 118 migrants were rescued from it by the Migrant Offshore Aid Station (MOAS) ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

A migrant, who has just been rescued, prays on a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) whilst being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants are helped to cross from their rubber dinghy to a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants are helped to cross from their rubber dinghy to a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants are helped to cross from their rubber dinghy to a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

A migrant jumps from a rubber dinghy to a Migrant Offshore Aid Station (MOAS) RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Live video footage transmitted from a Schiebel Camcopter S-100 drone showing a rubber dinghy packed with 118 migrants is seen on a monitor on board the Migrant Offshore Aid Station (MOAS) ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants react after boarding the Migrant Offshore Aid Station (MOAS) ship MV Phoenix some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants on a rubber dinghy wait to be rescued by the Migrant Offshore Aid Station (MOAS) ship MV Phoenix, some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)

Migrants reach out to grab hold of Migrant Offshore Aid Station (MOAS) rescuers on a RHIB (Rigid-hulled inflatable boat) before being taken to the MOAS ship MV Phoenix some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. (Photo by Darrin Zammit Lupi/Reuters)